Iatcien maurice



fNo. 625,892. Patented May 3o, |899.

L. MAURICE.

ACGUMULATDR 0F HEAT.

(Application filed May 28, 1898.

UNITED STATESV PATENT OFFICE.

LUCIEN MAURICE, OF PARIS, FRANCE.

Accu M U LATO R lor H EAT.

SPECIFICATION forming part of Letters Patent N o. 625,892,- dated May 30, 1899.

Application filed May 28, 1898.

Serial No. 682,055. (N0 mOdel.)

furnace by parting with the heat previously.

stored therein.

My invention is a commercial application of the property possessed by certain bodies, such as nitrate of potassium, employed either alone or mixed with other bodies, as will be hereinafter further explained, of fusing and then remaining liquid at high temperatures without becoming decomposed and without any appreciable pressure.

I will take as an example in order to explain my inventionfthe eutectic mixture (the word eutectic is explained farther on) of nitrate of potassium and nitrate of sodium in the proportion of 67.10 per cent. of the former body. In the solid state the density ot' this mixture is about 2.13. In the liquid state it is about two. Its mean specific heat is sensibly equal to 0.5. Its latent heat of fusion is thirty-five calories. It only acquires an appreciable pressure when above 525o centigrade by slowly parting with oxygen. Hence a ten-horse-power motor consuming twenty kilos of steam per horse-power, and which would thus need two hundred kilos of steam per hour, would Work without a iire for one hour with about six hundred kilos or three hundred liters of mixture forming the heataccumulator. The volume of the mixture serving as accumulator would thus at the lowest computation be equal to one and onehalf of the volume of water to be evaporated.

In the above example I have chosen very unfavorable circumstances; but in practice when the heating is effected simultaneously with that of the liquid heat-accumulator of the water and of the metallic mass of the apparatus the yield will be increased in large proportions and almost doubled. Finally and again, at the lowest computation the volume of the accumulator mixture will be at the most equal to the volume of water to be evaporated. The mixture previously mentioned is not the only one which can be used to thus form a heat-accumulator. The following mixtures are suitable,.and any one of them can be selected according to the circumstances of the application in view. The proportions can also be varied.y Nevertheless the proportions indicated correspond to what scientists designate the eutectic mixture, remarkable by the'iixidity of the point of fusion. According to the case one of the following mixtures can be taken:

I give below, so that the invention may be readily understood, one form of its application to a tireless boiler. The annexed drawings show one-mode of construction suitable to this application.

Figure 1 is a longitudinal section of the boiler, and Fig. 2 is a half-transverse section thereof on the line A Bof the previous figure.

A series of concentric tubes are arranged between two tube-plates l and 2, the annular` space 3 between the two tubes being iilled with a mixture of nitrates or other equivalent mixture forming an accumulator of heat. This annular space is closed at both ends; but

the central tube 4 of each element is in com- IOO steam=trams submarine boats, the., or for any l the bodies serving as heat-accumulators, as

other purpose. Vith the accumulator mixture just mentioned there is no risk of exceeding the limit of temperature at which the mixture decomposes, as, on the one hand, the tubes most exposed to the fire rarely attain in the furnace a temperature of 525, and, on the other hand, the commencement of the decomposition of the mixture is made known by the disengagement of oxygen, and for this purpose each one of the annular spaces 3 containing the mixture can be connected by a small tube 5 to a discharge-tube 6, through which the gas produced escapes in a continuous and easy manner, as may be ascertained by any suitable means-as, for inst-ance, by a sensitive manometer. Besides the advantages obtainable in Various industries by this system of heat-accumulator it will be readily understood that any chance of explosion by overheating is obviated, as up to the limit to which the temperature of the mixture employed is raised this latter becomes heated without acquiring pressure. It will thus be clear that this arrangement .can be applied, as before stated, to boilers Working under normal conditions and for which it is desired to insure absolute safety, the annular space 3, filled with the material, serving as an intermedium and protecting the tubes for the circulationof the Water from overheating at the same time that through the volume of heat contained in the accumulator-body the continuity of the temperature is insured even in case of sudden variations in the working of the furnace.

Having thus explained my invention and reserving to myself the rightto Vary according to the conditions of the application all accessory circumstances which might present themselves during the working of my invention, especially the natu re and proportions of Well as the option of reversing the reciprocal positions of the liquid to be evaporated and the bodies serving as accumulators, (the internal tubes or recipient-s 4 then containing the accumulator-body and the annular spaces 3 the liquid to be evapored,`) I claim and de= sire to secure by Letters Patent- 1. A heat-accumulator comprising a plurality of tubes connected at their ends with tube-plates, and a series of tubes arranged concentrically around said tubes each independent of the other and closed at their ends, and out of communication with said tubeplates and filled with a material capable of liquefying under heat, substantially as specilied'.

2. A heat-accumulator comprising a plu rality of tubes connected at their ends with tube-plates, tubes surrounding said tubes and disconnected from said tube-plates, and a filling of material capable of liquefying under heat arranged around each of the inner tubes within the outer tubes, the Iilling of each tube being independent of the others, as set forth.

3. A heat-accumulator comprising a series of tubes, connected at their ends to tubeplates, tubes surrounding the said tubes and .disconnected from said plates, a filling of material capable of liquefying under heat in the space between the tubes, each iilling being independent Ot' the others, and a' pipe common to all of the spaces around the inner tubes for allowing the escape of gas, substantially as and for the purpose specified.

In testimony whereof I have hereunto set my hand in presence of two lsubscribing witnesses.

LUCIEN MAURICE.

XVitncsses:

EDWARD P. MACLEAN, ALFRED FREY. 

